This invention pertains to methods for assessing neuromuscular reflexes non-invasively for persons with lower back pain.
The invention provides such a method for assessing neuromuscular reflexes through surface electromyography (EMG) simultaneously during stiffness assessments. It is a primary object of the present invention to determine the stiffness index and neuromuscular characteristics of the asymptomatic and symptomatic low back pain in subjects reporting the same. These and other advantages of the present invention, as well as additional inventive features, will be apparent from the description of the invention provided herein.
Physical examination of patients with low back pain (LBP) has included assessment of the motion of the human spine in an attempt to assess the functional status of underlying anatomy. Clinicians have utilized mobilization palpation procedures to manually apply posteroanterior (PA) forces over various spinal segments to assess the perceived tissue resistance and pain provocation. The clinician further uses the perceived results of these assessments to formulate clinical diagnoses and to identify which spinal level to treat and supposed effectiveness of the intervention. Due to the qualitative nature of such assessments, however, many studies have demonstrated that such clinical judgments are unreliable or inaccurate (22, 39, 43, 48). For this reason, mechanical devices have been developed to more objectively quantify spine stiffness.
A series of studies have appeared investigating the reliability and validity of instruments to assess spine stiffness with favorable results. Spinal disorders may be characterized as exhibiting alterations in the mechanical behavior to loading, notably, changes in spinal stiffness. Studies investigating posteroanterior (PA) forces in spinal stiffness assessment have shown relationships to spinal level, body type, and lumbar extensor muscle activity. Such measures may be important determinants to discriminate patients with low back pain and further provide significant information of the mechanical behavior of the human spine. Little objective evidence is available however, discerning variations in PA stiffness and its clinical significance.
Although ligaments have been considered to provide primary restraint to most major joints, recently the musculature has been shown to play an important role in maintaining joint stability. Solomonow and associates reported that mechanical deformation of ligamentous tissues of the human spine could reflexively elicit activity of the paraspinal muscles providing a net effect of stiffening of the motion segment. As the spine is a complex dynamic structure whose viscoelastic makeup includes not only its discoligamentous elements, but also stabilizing musculature, we aimed to study mechanical and neuromuscular responses to dynamic PA manipulative thrusts. Specifically, the objective of this prospective clinical study was to investigate the mechanical PA stiffness of the thoracic, lumbosacral, and pelvic regions and concomitant lumbar neuromuscular responses to high loading rate PA thrusts in a group of subjects with varying degrees of LBP.
The research conducted by applicants was presented, in part, at the 26th Annual Meeting of the International Society for the Study of the Lumbar Spine, held in Kona, Hawaii, Jun. 21-25, 1999. A copy of applicants"" full report is attached hereto and incorporated herein by reference.
The invention may best be understood with reference to the accompanying drawings and in the following detailed description of the preferred embodiments.